%I #34 Jan 22 2021 20:29:54
%S 1,2,3,4,5,6,9,11,17,19,23,25,29,37,41,47,49,53,59,61,67,71,79,83,89,
%T 97,101,103,107,109,113,131,137,139,149,151,163,167,169,173,179,181,
%U 191,193,197,199,223,227,229,233,239,251,257,263,269,271,277,281
%N Numbers that are not Brazilian numbers.
%C From _Bernard Schott_, Apr 23 2019: (Start)
%C The terms of this sequence are:
%C - integer 1
%C - oblong semiprime 6,
%C - primes that are not Brazilian, they are in A220627, and,
%C - squares of all the primes, except 121 = (11111)_3.
%C So there is an infinity of integers that are not Brazilian numbers. (End)
%C This sequence has density 0 as A125134(n) ~ n where A125134 is the complement of this sequence. - _David A. Corneth_, Jan 22 2021
%D Pierre Bornsztein, "Hypermath", Vuibert, Exercise a35, page 7.
%H David A. Corneth, <a href="/A220570/b220570.txt">Table of n, a(n) for n = 1..10000</a> (first 1000 terms from T. D. Noe)
%H Bernard Schott, <a href="/A125134/a125134.pdf">Les nombres brésiliens</a>, Quadrature, no. 76, avril-juin 2010, &6 page 36; included here with permission from the editors of Quadrature.
%e 25 is a member because it's not possible to write 25=(mm...mm)_b where b is a natural number with 1 < b < 24 and 1 <= m < b.
%o (PARI) for(n=1,300,c=0;for(b=2,n-2,d=digits(n,b);if(vecmin(d)==vecmax(d),c=n;break);c++);if(c==max(n-3,0),print1(n,", "))) \\ _Derek Orr_, Apr 30 2015
%Y Cf. A125134 (Brazilian numbers), A190300 (composite numbers not Brazilian), A258165 (odd numbers not Brazilian), A220627 (prime numbers not Brazilian).
%K nonn,easy,base
%O 1,2
%A _Bernard Schott_, Dec 16 2012